The communications industry is rapidly changing to adjust to emerging technologies and ever increasing customer demand. This customer demand for new applications and increased performance of existing applications is driving communications network and system providers to employ networks and systems having greater speed and capacity (e.g., greater bandwidth). In trying to achieve these goals, a common approach taken by many communications providers is to use packet switching technology.
Packet switching devices determine the order of packets processed by, and sent from, a packet switching device typically based on a number of parameters including different Quality of Service (QoS) for different types of packet traffic. A scheduling system typically consists of a cone (tree) of scheduling decision points starting with the queues at the top and working through several layers of hierarchy down to a root decision. Each layer typically corresponds to different grouping, such as, but not limited to, subscribers, VLANs, ports, interfaces, etc. At each node in the scheduling system, service is distributed typically based on configured QoS parameters such as, but not limited to, minimum and maximum rates, excess bandwidth sharing, priority level(s), and propagation characteristics.